Air-brake mechanism



nOet. 20, 1925. 1,558,374

' l. D. LENGEL AIR BRAKE MECHANISM Filed Sept. 8, 1924 YI5 Sheets-Sheet l oct. 20, 1925.

l. D. LENGEL AIR BRAKE MEGHANISM Filed Sept. s, 1924 3 Sheets-Sheet 2 Patented Det. 2t), 1925. i

UNITED STATES IRVIN' D. LENGEL, OIE READING, PENNSYLVANIA, ASSIGNR T LENG-EL COMPANY, 0F

WILMINGTON, DELAI/WARE, A COREORATION F DELAWARE.`

AIR-Banni; MncHANIsM.

Application filed September 8, 1,924. SerialNo. 736,617. i

To all to/wm 'it 'may concern Be it known that I, InvrN D. LnNGnL, a citizen of the United States, residing' in Reading, Berks County, Pennsylvania, have invented certain Improvements in Air-Brake Mechanism, of which the following is a specification.

My invention relates to certain improve ments in air pressure brakes for vehicles, especially automobile omnibuses and trucks.

The object of the invention is to improvel the construction of the air brake mechanism so that the pressure will be applied progressively, thereby preventing the locking of the wheels and the sliding of the Wheels on the pavement or roadway. This sliding action causes the surface of the tires to wear rapidl lldy my invention, a comparatively light pressure is applied, which allows the wheels to turn under friction, after which full pressure is applied, which stops the movement of the vehicle.

In the accompanying drawings:

Fig. 1 is a side view of my improved air brake mechanism, showing it attached to the frame of an automobile omnibus;

Fig. 2 is a sectional view on the line 2 2, Fig. 1;

Fig. 3 is a sectional plan view on the line 3 3, Fig. 2; y

Fig. l is a diagrammatic plan view, showing the arrangement of the brake cylinders and the control Vvalve on the frame of an automobile; and

Fig. 5 is a view illustrating a modification ofthe invention.

The frame 1 of the vehicle is made of channel bars in the ordinary manner, as shown inFig. 1. .The brake cylinders 2 are secured to the channel bars by brackets 8. li, 4 are the rear wheels of the vehicle. 5, 5 are the brakes, which are controlled through lever mechanism (i, connected by rods 7 to the levers 8 of the cylinder structure.. An air pressure tank 9 is located at any suitable point and is connected by an air line 10 to an accumulator on the engine structure of the vehicle to which the brake mechanism is applied.

The control valve 11l is secured to the framework of the vehicle and is operated, preferably by the foot, to allow air under pressure to enter the cylinders through pipes 12 `and 13. v The air is'supplied to the valve through a pipe 10a, which is connected to the air pipe .10. The` air is exhausted from the valvethrough the pipe 14.

The diagram, Fig.' 4, illustrates thelocation of the different parts hereinafter described. It will be understood that the arrangement may be modified without departing from the essential features of the invention. Y Y

Referring to Figs. 1 and 2, the'cylinder 2 is open at the bottom and is closed at the top. The top 15` is formed, as shown in Fig. 2, and is preferably made integral with the cylinder. The cylinder has a base flange 16, which is secured to the base 17 that forms an integral part of the bracket 3, in the present instance. Mounted within the cylinder 2 is a cylindrical piston 18, `which is closed at both ends. The lower end 19 is preferably an integral part of the cylindrical piston 18, while the upper end 2,0 is'in the l form of a plug having a threaded periphery, the threads of which engage threads on the cylindrical piston. `Between a shoulder 21 onthe cylindrical piston and the head is a packing ring 22 to make the joint air tight; The end 19 of the cylindrical piston bears against the arm 23 of the bell-crank lever 8, which is mounted on a pivot pin 24, carried by brackets l25 that form an integral part of a. plate 26, which is secured to the under side ofthe bracket 3. The arm 27 of the lever 8 is connected to the brake mechanism by rods 7, Fig. 4. ,f Within the cylindrical piston 18 is a` fixed abutment 28, which is mounted on a stem 29 that is secured to the top 15 of the cylinder by a nut 8O that is mounted Von, the threaded portion of the stem. In the stem is a passage 31. The pipe 12 is coupled to this stem, and, when air, under pressure, is

admitted to the pipe 12, it passes through the stem into the space a between the fixed abutment and the bottom of the movable piston, projecting the. movable piston and causing the lever mechanism primarily to apply the brakes. Communicating with the space b between the head 20 of the cylindrical piston 18 and the cylinder 2 is a passage 32, which communicates with the pipe 13 that leads from-the control valve so that` when air is admitted through the pipe 13 and the passage 32, pressure is applied on Cit an increased area of the cylindrical piston, causing it to apply the brakes with suiiicient pressure to stop the vehicle.

In the head 20 is a packing 33 that is held in place by a follower 34, which is screwed into the head, as shown in Fig. Q. The periphery of the cylindrical piston 1S has grooves in which are annular packing rings 34. ln the periphery of the fixed abutment are grooves having lannular packing `rings 35. A vent 36 is provided 'lor the space between the lined abutment 28 and the head 20 to allow' the cylindrical piston i8 to move forward easily.

In Fig. 5, a modification is illustrated, in which the cylinder 2f" is made substantially as shown in Fig. 2. l/Vithin this cylinder is a cylindrical piston 18 that is open at the bottoni and is closed at the` top. lF-Jithin the cylindrical piston 18 is a second cylindrical piston 18h that has an external iiange 37 against which the end of the piston 18 comes in Contact, when projected. `lVithin the cylindrical piston 18h is a third cylindrical piston 18C. The piston 18a has a langed head 38. lVitliin the cylinder 2 is a tubular stein 29a that has passages 3l and 31h, which communicate with the spaces o', b and c. Suitable packing is provided, as shown. The mechanism illustrated in Fig. provides three pressures.

While the invention is shown as brakemechanism for automobiles, oinnibuses and trucks, it will be understood that the invention can be applied to the brake mechanism of other vehicles7 such as railway cars, &c., without. departing from the spirit of the invention.

l claiml. The Vcombination in brake mechanism, of a cylinder; an abutment extending into the cylinder; a hollow piston located` between the abutment and the walls ol the cylinder, said piston having a plurality of pressure surfaces; and .means Yfor successively applying` fluid to said surfaces ot' the piston to project the piston and to apply the brakes.

2. flhe combination in brake mechanism, ot a cylinder; a hollow piston having a closed end; an abutment secured to the cylinder and extending into the piston, said piston having tw pressure surfaces; and means forsuccessivelyapplying fluid, under pressure, to the surfaces of the piston.

3. The combination in brake mechanism 'tor vehicles, of a cylinder; a hollow piston in the cvlinder having closed end and eX- tending beyond the end ot the cylinder; a lever; a bracket to which the lever is pivoted, said piston Yiniaring against one arm ot' the lever, the piston having two pressure surfaces; an alnitnzenty secured to the cylinder and extending into the piston; means admitting i'inid, under pressure, to the spaces between the abut-nient and the end oi' the pist:` ar l fluid, under pressure, between the end oiI the cylinder and the piston.

e'. rlhe combination in brake mechanism lor vehicles, olf a cylinder; an abutmentin the cylinder; a piston located between the 'cylinder and the ahuti'nent; two ports for supplying fluid to projectv the piston; a va fe controlling the admission of fluid to the cylinderj` a lei' actuateddiy the piston; and a brake connected to the lever.

The combination in air brake mecha- Anisni for motor driven vehicles, of two cylinders; a piston in each cylinder; means for applying two'pressures to each ot said pistons; brake mechanism at each side of the vehicle; a lever actuated by eacn of said pistons, each lever being connected to a brake mechanism; an accumulator at the motor; and a valve controlling the How of air under pressure to the cylinders.

(l. The combination in brake mechanism Jfor vehicles, oi a cylinder open at one end; an abutment located within the cylinder and having a stem secured to the closed end o'i the piston; a hollow piston within the cylinder, the aluitment litting the interior ot' the cylinder; a screw plug closing one end oi" the piston; packing between the plug and the stem of the abutment, said stem bcing hollow throughoutits length for the passage yof Huid; and `a .Huid passage communicating with the space between the end ot the cylinder and the piston.

IRVIN D. LENGEL.

means for admitting 

